1. Field of the Invention
The present invention relates to a liquid crystal display module (LCM) that may be easily assembled and a method for assembling the LCM.
2. Discussion of the Related Art
Uses for an LCM have gradually increased due to its light weight, thinness, and low power consumption. LCMs have wide applications including office automation and audio/video devices. The LCM operates by adjusting transmittance quantities of light in accordance with image signals applied to a matrix of control switches, in order to display desired pictures on a screen. That is, the LCM is not a spontaneous light-emitting display device. The LCM typically needs an accompanying backlight unit as a light source. There are two types of backlight units for the LCM, i.e., a direct-lighting type LCM and an edge-lighting type LCM.
Typically, an edge-lighting type LCM includes a liquid crystal display panel, a backlight unit, a bottom frame, an upper frame, and an outer protecting frame. The upper frame is attached to the bottom frame defining a chamber for receiving the backlight unit. The liquid crystal display panel is supported at the top of the upper frame and covers the backlight unit. The backlight unit usually includes light sources such as cold cathode fluorescent lamps, a light guide plate, and a plurality of optical elements such as a light reflective sheet, a light diffusion film, and a prism sheet. One edge of the liquid crystal display panel is electrically connected to a flexible printed circuit that may be curved to connect with a printed circuit board positioned under the bottom frame.
The LCM is assembled by fixing the light sources to the sides of the bottom frame. The reflective sheet, the light guide plate, the light diffusion film, and the prism sheet are positioned at the base of the bottom frame in order, with the light sources facing the light guide plate. The upper frame is attached to the bottom frame to secure the backlight unit. Then, the liquid crystal display panel is placed on the upper frame to avoid contact with the light diffusion film, the flexible printed circuit is wrapped along a side of the upper frame, and the printed circuit board is positioned under the bottom frame. Finally, the outer protecting frame is mounted on the liquid crystal display panel and fixed with the printed circuit board and the bottom frame tightly.
Under this process, the liquid crystal display panel can easily shift before assembling the outer protecting frame. Much care and high precision are required to assemble the outer protecting frame. The process involves the risk of damaging or scratching the liquid crystal display panel. Thus assembly of the LCM can be unduly complicated, troublesome, and costly.
Therefore, an improved LCM and method for assembling the LCM are desired to overcome the above-described deficiencies.